The present invention relates to an apparatus for packaging products in open or closed boxes, starting from a flat paperboard material.
As is known, for packaging loose products, such as tins, bottles, cans and the like, flat paperboard sheets are conventionally used, said paperboard sheets being so shaped as to provide a desired tray or closed box configuration.
An apparatus using such a packaging is disclosed, for example, in the document DE-3 515 248 which illustrates a paperboard sheet which is horizontally arranged at a loading region, where one of the side flaps, horizontally arranged, is preliminarily bent to a vertical position.
The article assembly is displaced perpendicularly to the side flap toward the base panel and is arranged on said panel.
Then, the other side panel is upward bent, whereas the flaps are inwardly bent.
The thus formed package is driven toward the side panel, which has been raised at first, and which is arranged perpendicular to the article being packaged inlet direction.
This apparatus causes a variation of the driving or supplying direction, which greatly hinders a quick operation of the apparatus, since the articles to be packaged must be temporaneously held in a stop position, which requires a comparatively long time due to the article stop time and the deceleration and acceleration times.
Moreover, the above disclosed apparatus requires specifically designed supporting elements in order to lock the flaps against the package, after having inwardly bent said flaps, to allow the glueing material to cure to provide a firm connection.
It should be apparent that all the disclosed additional devices greatly add to the cost of the apparatus.
The document U.S. Pat. No. 4,571,916 discloses a packaging apparatus in which the paperboard sheets are supplied simultaneously with the articles to be packaged in the same supplying direction.
After having arranged the articles on the base panel, and with the articles and paperboard sheets being driven, the front and rear flaps are upwardly bent through 90.degree. and then are correspondingly bent the side panels to cause said side panels to be vertically arranged.
Such an apparatus must necessarily comprise specifically designed implements for handling the panels and flaps, which implements are driven along the conveyor belt together with the package, in order to hold each element in its set position, to allow the glue material to properly cure.
The above apparatus is very complex construction wise and, moreover, its cost is comparatively high.
The document U.S. Pat. No. 3,844,088 provides a solution in which the finished package is driven away in the same direction in which the paperboard sheet is supplied to the apparatus loading region, fixed bending implements being provided for upwardly bend the side walls or panels.
Even in this case it is necessary to provide a clamping device, like that shown in the document DE 3 515 248, for holding the package together to allow the glue material to properly cure.
The document CH 478 026 discloses a packaging system provided for packaging multiple articles, in which the packaging paperboard sheet is upwardly bent according to a "U" shape, with the flaps or legs raised to a position perpendicular to the driving or supplying direction.
This apparatus comprises two specifically designed devices for closing the end portions of the package, each of said devices comprising two closing elements for closing the largest panels.
These closing elements, in particular, must be designed for movement along the conveyor belt, in order to make the package.
Accordingly, the packaging process requires a comparatively long time and is very complex.
The document U.S. Pat. No. 5,149,654 discloses a packaging apparatus in which the side flaps are prebent, after having raised the paperboard sheets.
The base flaps are pre-bent upwardly through 45-80.degree. and are held in this position by means of lever elements, and then the side panels are upwardly bent through 90.degree.; finally, the top and front base flaps are pressed together with the base and rear top flaps of the preceding package and being held in this condition to allow the glue material to cure.
This packaging process too is very long, complex and expensive.
Moreover, for changing the paperboard sheet size, it is necessary to perform comparatively long and complex operations.